Citing Health Concerns, Some Cities Consider Dimmer LED Streetlights

 In the last several years, New York, Los Angeles, Houston, Seattle and other U.S. cities have installed high-intensity, white LED streetlights. In all, at least 13 percent of outdoor lighting is now LED, and many communities that haven’t yet made the switch are rushing to do so. But health concerns, heightened by a recent warning by the American Medical Association (AMA), are giving pause to some local officials, spurring them to consider less-intense LED alternatives. Honolulu, Phoenix and smaller cities in Arizona, California, Florida and Massachusetts are among those who are taking the health warnings seriously.

Cree revamps entire LED line of better bulbs

Cree, Inc. announces a completely new portfolio of next generation LED bulbs aimed at delivering better light experiences for consumers. The new bulb portfolio consists of 25 new products, offering better light quality, better dimming, better lifetime, better warranty and better pricing to deliver on the true promise of LED technology to make lighting better than it was before.

“Cree is committed to innovation and unlocking the true potential of LED technology,” said Betty Noonan, Cree chief marketing officer and general manager, consumer lighting. “Many new LED products fail to live up to the promise of LED technology; shouldn’t you choose a better bulb when it will live in your house for decades?  Cree believes it’s now more important than ever to give consumers a better choice.”

Notable features in the new bulbs include superior lifetimes, with most projected to last 22+ years and some up to 32 years.  Color rendition is improved, with smoother, quieter dimming to levels as low as 1 percent.  Cree’s market-leading “Candlelight Dimming,” available in the new candelabra bulb, mimic’s a true candle flame with a warmer 1800K color when dimmed.

The new Cree bulbs meet or surpass the requirements for ENERGY STAR product certification and are covered by a 10 year 100 percent satisfaction guarantee – one of the strongest warranties in the industry. The new bulb portfolio includes new A-lamps, BR lamps, PAR lamps and Candelabra lamps, as well as a new series of recessed downlight retrofit products.

Achieving Optimum LED Performance With Quantum Dots

The invention of blue LEDs and the subsequent rapid rate of development of new phosphor and down-converting technologies have enabled the phenomenal growth of all LEDs in general lighting applications. White LEDs initially employed the use of a blue LED combined with a single phosphor with broad yellow emission. However, the light quality provided by this relatively simple solution was less than satisfactory, particularly in the red part of the visible spectrum. But more recently, new phosphors and phosphor combinations (green-yellow plus red) have been developed to provide a higher quality of light. While these advancements afford a significant improvement over previous offerings, phosphor technologies have yet to deliver desirable white light with rich color rendering ability along with the energy efficiency typically attributed to LEDs.

Infrared LED revenue growing faster than overall IR components

Increased adoption of biometrics security in mobile phones, close-circuit television and other consumer applications spurred revenue growth in the global market for infrared LEDs from $201.5m in 2014 to $241.4m in 2015, according to Jamie Fox, principal analyst, LEDs and Lighting, at IHS Markit. While infrared LEDs grew 19.8% year-on-year in 2015, the overall infrared components market fell by 9%. Osram, Everlight and Vishay were the leading suppliers. 

Common infrared LED that emits infrared rays has the same appearance with visible light LED. Its appropriate operating voltage is around 1.4v and the current is generally smaller than 20mA. Current limiting resistances are usually connected in series in the infrared LED circuits to adjust the voltages, helping the LEDs to be adapted to different operating voltages. 

An IR LED, also known as IR transmitter, is a special purpose LED that transmits infrared rays in the range of 760 nm wavelength. Such LEDs are usually made of gallium arsenide or aluminium gallium arsenide. They, along with IR receivers, are commonly used as sensors.

The appearance is same as a common LED. Since the human eye cannot see the infrared radiations, it is not possible for a person to identify whether the IR LED is working or not, unlike a common LED. To overcome this problem, the camera on a cellphone can be used. The camera can show us the IR rays being emanated from the IR LED in a circuit.

Measurement basics in LED thermal management

A successful LED design needs a balance of form and function to be a desirable luminaire with the right lumen output. Sounds simple enough, but these two requirements are often in conflict. When form trumps function, LEDs that are usually mounted onto a metal-clad PCB (MCPCB) as a module are all too often crammed together, creating a module with high-power density. If the device has not been designed to remove the heat from the LEDs effectively, there is a real risk of the LED overheating. As with any semiconductor, when LEDs overheat efficiency is reduced, light quality deteriorates, lifespan shortens and ultimately the LED can catastrophically fail.

Indian Bulb Maker Eveready Acquires Large Order from EESL

Indian LED manufacturer Eveready Industries acquired a large order of 1.3 million LED tube lights from the state-owned power company Energy Efficiency Services Ltd. (EESL), reported Business Standard.
The EESL order values an estimated INR 179.4 million (US $2.67 million).
“The company has obtained a letter of award from Energy Efficiency Services Ltd for design and supply of 20W external batten LED tube light on pan India basis,” stated Eveready in a press release.
EESL is a joint venture formed by Indian power companies NTPC Limited, PFC, REC, and Power Grid Corporation to implement energy efficiency projects, and also works as an energy services company. The organization is responsible for implementing India’s Domestic Efficient Lighting Program (DELP).
Everready is one of the leading manufacturers of batteries and flashlights, and sells more than 1.2 billion batteries and nearly 25 million flashlights. The company also makes LEDs, CFLs, and GLS lamps and other lighting products, small home appliances and tea.

Fujian achieves breakthrough in LED technology

Fujian province has seen the technological breakthrough of LED technologies for transparentfluorescent ceramic material that allows dense LED lights to concentrate on a small surface. The technology has been co-developed by Research on the Structure of Matter (FJIRSM) andFujian Zhongke Xinyuan Optoelectronics Technology Co Ltd. “With previous technologies, Chinese LED manufacturers were not able to produce largepower LED,” said Hong Moachun, academician at FJIRSM, “because when the light runs formore than 200 watts, the LED lights will produce too much heat on a small surface that coulddamage the light. Therefore, these LED lights are used only for ordinary lighting. ”

Nanocrystals speed up Wi-Fi-emitting LEDs

Communication technologies like Bluetooth and Wi-Fi operate on invisible radio waves, but transmitting data on wavelengths we can see might turn out to be more efficient and secure. Researchers at King Abdullah University of Science and Technology (KAUST) have developed a nanocrystal that helps boost data speeds transmitted through a visible light LED up to 2 Gbps – while pleasantly lighting the room.

Communication technologies such as Wi-Fi and Bluetooth operate on invisible radio waves, but it turns out, transmitting data on visible wavelengths may be more efficient and secure. A team of researchers at King Abdullah University of Science and Technology (KAUST) in Saudi Arabia developed a nanocrystal that helps boost data speeds transmitted through a visible light LED up to 2 Gbps while also lighting up the room.

Because just a fraction of the electromagnetic spectrum can be seen by the human eye, making use of those wavelengths could mean faster, safer wireless data systems. With so many wireless signals zipping around, certain frequencies can become clogged, and radio waves can interfere with sensitive equipment, such as those used for navigation or in hospitals. Visible-light communication (VLC) systems can help bypass these issues.
Currently VLC devices are based on LEDs, which use phosphorus to turn some of the blue light emitted by a diode into green and red. When combined, the colors form white light to comfortably light a room while also providing a wireless signal. But as you’re likely aware, this technique comes with limits.
“VLC using white light generated in this way is limited to about one hundred million bits per second,” said KAUST Professor of Electrical Engineering, Boon Ooi. However, a University of Virginia study reached 300 Mbps, and Siemens managed 500 Mbps. Pennsylvania State University has even hit 1.6 Gbps using invisible infrared light.
As for the researchers at KAUST, they’ve achieved 2 Gbps using visible light, converting the colored light into white using nanocrystals instead of phosphorus. At 8 nm long, the crystals are made of cesium lead bromide, and when hit by a blue laser, emit green light. An incorporated nitride phosphor emits red light, and the three colors combine to form the white, room-illuminating light that's comparable to that of existing LEDs.
In nanocrystals, the optical processes operate on a time-scale of about seven nanoseconds, meaning the optical emission of the light operates at a frequency of 491 MHz. This allows the data to be transmitted at 2 Gbps. Data is transferred through a series of flashes, undetected by the human eye, but clear to a receiving sensor.
The research was originally published in the journal ACS Photonics.